#! /usr/bin/env python
# -*- coding: utf-8 -*-
# vim:fenc=utf-8
#
# Copyright © 2019 crane <crane@gosun>
#
# Distributed under terms of the MIT license.

"""

"""

def left_area(down_percent, up_area, left_right_percent):
    half = up_area / (0.5-down_percent) / 2
    return left_right_percent / (left_right_percent + 1) * half


def main():
    print("start main")
    l = left_area(0.2, 18, 5/7)
    print("left area is", l)

    l = left_area(0.15, 21, 5/7)
    print("left area is", l)

if __name__ == "__main__":
    main()
